Ice Pop Mold Problems

Are you using plain plastic molds that you just fill and put in the freezer, or those modern 'Zucco' things that have a freezing liquid inside the outer box (I've tried those, and been disappointed - too fiddley)?

With the plain plastic, yes, before giving up, I'd try drilling holes in the sticks. Use a hand-drill, as the softish plastic will probably jam a power tool. Make the holes small, so there's enough left to be a sturdy stick, and you'd only need two/three for the liquid to flow through. Wash the sticks really well after the drilling, in case there's any residue. If that doesn't work, then, maybe get another set (checking the sticks first) and repurpose the set.

To your other question, about the fruit-pops, I'm diabetic and if you don't want to mess around with sweeteners, how about just using fruit? Nice, juicy, fresh fruit. (You could use canned, in water or juice, for convenience or variety.)
Puree the preferred fruit, maybe a little water or milk (or yogurt or juice) to thin it for pouring/texture, anything that seems appropriate as spices, pour into pops to freeze. Applesauce and cinnamon is good, or pears and a very small dab of ginger. Essentially, the milder the fruit, the more you might want to add a little something. Really ripe peaches are nice. Because it's pretty much straight fruit, if you measure how much fruit goes into a pop mold, your dad can just count it as the equivalent in fruit.

There are books on ice-pop recipes, most of them are complicated or add sweeteners, but if your local library has any, you might try them for ideas. Or, on-line, I'm betting that some of the big on-line recipe places have ideas.

Move farther north, to where I live, Frimble, and make these in January. Just put 'em outside, you'll have no trouble at all.

caw

What Frimble said about the molds, though I'm wondering if the rocket ones were completely frozen, as I used to have molds and none had holes in the sticks and that didn't happen, so maybe they just weren't as solidly frozen as could be?

As to recipes, you can do stuff like mix a fruit base (either some plain chopped fruit or some fruit cooked down a little, but if you do that, I'd add at least a bit of apple juice or a spoon of agave or something) in with plain, unsweetened greek yogurt that you mix some vanilla (or orange or lemon or whatever the heck) extract into. If you mix up the yogurt with some extract first, then swirl in some fruit you'll get a swirly pop. You can do just yogurt with an extract (or not if you like the yogurt plain), or mixed with some coconut milk (not water) too.

Plain greek yogurt has a bunch of protein, not a lot of calories, no added sugar and it's thick and creamy and freezes well.

Google "paleta recipes" for a lot of good ideas for fruit-based pops (some of which don't have any extra sugar at all). Here's an assortment.